The Spittoon » Find Your Inner Neanderthal (I retract what I said before: the results are coherent, even if Africans still get too much too often I guess that’s part of the margin of error. However there is another “free online” genetic test that is misleading).

Biology and psychology

Of mice and men, a common cortical connection – a nice comparison to better understand brain regions. To the right: F/M: frontal/motor cortex, S1: primary somatosensory cortex, A1: primary audtive cortex and V1: primary visual cortex. Mice have a much more developed somatosensory cortex (surely related to whiskers, smell, etc.) but a much less developed frontal/motor cortex (related to willpower and rationality).

11 responses to “Echoes from the Past (Dec 26)”

Hi Maju, very interesting news!"Take with a good dose of salt: I've been seeing results online that are totally inconsistent with what we know of Neanderthal admixture in Europeans (and in general): while the norm should be 2.4%, the results provided by 23&me are all above 6%, so something is very wrong with their method. "Really!? I've been following the discussion on this forum: http://www.forumbiodiversity.com/showthread.php?t=26598And people usually score between 2 and 3%. What's not expected, however, is that some Africans seem to have N-admixture, indeed, though at lower levels than non-africans."long sleeping is a genetic need: tell your boss next time you are late. I am among those who need to sleep 9-10 hours per day (normally) though I have also met people who only sleep 4-5 hours"LOL. I know some people who always feel asleep. I'm the odd case: sometimes I do it fine with 5 hours, yet when I can, I sleep up to 9-10 hours too."Why aren't we smarter already? Evolutionary limits on cognition"Really? I've read upper paleolithic HAM had bigger brains than us. Maybe they were smarter?"Brain Scans Reveal Difference Between Neanderthals and Us | LiveScience – something about the sense of smell, not too clear."Something about olfactive and frontal lobes. They say in 100.000 year old HAM these are bigger, but how big is the sample? 2-3? And what about present day humans? I'd be surprised if it turns out that we have better sense of smell than neanders…

My bad and correcting ipso facto. I happened to stumble upon this thread yesterday while searching for something else (not my favorite forum, really) and got confused: the test they were taking was a free online one and not the 23 and me one. It did not even say % but people interpreted it like it (17% Neanderthal, go figure!)

"Really?"Actually I had to re-read it and it seems a junk article that says little more than nothing. There may be limits however but the article does not help at all with understanding them. Personally I think that intelligence correlates with desire for freedom, frustration at seeing mediocre people ruling the world and rebelliousness (all correlated) and that therefore it is less selected for than it would be natural, because the hierarchical nature of the system hinders free thought and most intelligent initiatives. But maybe I'm just another frustrated above-the-average mind.My hypothesis is anyhow that civilization hurts intelligence by hurting creative freedom (even if also opens other avenues of knowledge, these may not compensate and in general mediocrity is selected for sadly enough).

By the way (advance notice), I have been toying with ADMIXTURE and European populations and I have stumbled upon a very strange component almost only found (at least >2%) among Slovenians, who display 22%. The component is stubborn in spite of its numerical insignificance at European level but crucially it displays Fst distances to all other components between 0.238 and 0.315. By comparison the greatest Fst distance among the three continental populations of the World (separate run with the same program) is of 0.195. Of course I do not know what to think but I recalled immediately that Heraus and I commented at his Anthroeurope blog how certain composites of Slovenia and Red Ruthenia (SE Poland) were very anomalous. I wonder if there is a pocket of extra Neanderthal admixture in those areas or, otherwise, what the heck does this component indicate?I'll discuss this more extensively soon. It may well be a false alarm but I'm most intrigued.

Neandertalerin: "What's not expected, however, is that some Africans seem to have N-admixture, indeed, though at lower levels than non-africans." Since there are clear tracks of Eurasian back migrations in African populations, it's to be expected, on the contrary (unless it's in population with no such known tracks, of course).

First, the very inference of Neanderthal admixture in Eurasian is based in triangular comparison with Africans (Yorubas and Bushmen) and Neanderthals. Africans displayed in the original paper (Green 2010 if I remember correctly) a variable amount of Neanderthal affinity (from negative to 0.5%) that was considered negligible (error margin) from the very beginning. It was assumed that such variation was part of the human diversity, possibly retained since before Neanderthal-Sapiens divergence. Second, a backflow from Eurasia of, say, 1% (a huge figure for most of Africa) would mean 0.02% or 0.03% Neanderthal ancestry, not 0.5%. You'd need Eurasian admixture levels of of 20% in order for that to be possible. While this may be the case among Maasai or Ethiopians, it's certainly not possible in West Africa (Igbos scoring 0.5-0.7% is not because of back-flow but because of the uncertainties involved). Unless you have some reason to think that Igbos and Zimbabweans (0.9%, there are Eurasians/Native Americans with less than that!), in contrast with say Ghanaians, have some notable Eurasian ancestry, what I do not. It's just random variation.That actually makes the case for finding out the exact percentage (to the decimal point!) of Neanderthal ancestry the more hilarious. But other than wasting money it's harmless and I'd dare say even informative.

"By the way (advance notice), I have been toying with ADMIXTURE and European populations and I have stumbled upon a very strange component almost only found (at least >2%) among Slovenians, who display 22%. The component is stubborn in spite of its numerical insignificance at European level but crucially it displays Fst distances to all other components between 0.238 and 0.315. "That's very interesting! However, I have some thoughts:1-If this 22% in Slovenians indeed come from neanderthals, why wasn't it possible to detect until now? As far as I know there have been numerous experiments with ADMIXTURE, and none found this component.2-How can it be possible for Slovenians to be 22%, while other neighboring populations have undectectable levals of it?3-Initial comparisons of CEU, Tuscans, Russians, French and Swedes yield very similar results to those of East Asians relative to neandertal ancestry (about 2.6%). Middle Easterners carry the same amount or even slighty less!4-If Slovenians carry a significant amount of neandertal heritage, how come we're unable to detect differences between them and other European populations? On the contrary, if that's the case, we'd expect to find them very separated from say, Tuscans or other Eastern Europeans, yet this doesn't seem to be the case. European "outliers" are the Basques, Sardinians, Finns and South Italians:http://blogs.discovermagazine.com/gnxp/files/2010/07/genmap1.jpg5- If true, that'd mean Slovenians have remanined quite isolated for the last 40.000 years, relative to all other European populations. I find this hard to believe.6-Such an high amount of neandertal heritage may allow us to find mtDNA and Y-chromosome lineages from neandertals. We've been unable to find them in any living population to date.As for the images of Slovenians, I don't know what to think. It's true some of them look odd, but being honest, I've never seen a real neandertal, so I have no idea of what's their true appearance, and reconstructions aren't a reliable source either. That being said, I find this very interesting and intriguing. Neandertals are obviously a possible source, but there are other possibilites (for example, the massive trade of African slaves fom a remote tribe to Slovenia a few millenia ago, I know it's even less likely).

I'm saying nothing but my best ideas after finding an issue, which are too tentative and feeble to withstand any attack. No idea in other words: it may all be a bug or an error in the sample. I just explained the whole exercise I run and how since K=6 (look for that subsection) I found this persistent and hyper-odd Slovene component. The issue is the almost transcendental eternal question: "bug or feature?"I hope for a bug, I'd gladly stand corrected and admit it was all an illusion, an error. It's too odd to think otherwise. But who knows? I leave the Neanderthal gate open until someone slams it on my face.

From 'Humans may have originated near rivers – Technology & science – Science – LiveScience – msnbc.com': "beach (river banks) was the favored ecosystem even for old good Ardi, it seems". Beach? That's not what the article claims: "All in all, carbon isotope ratios suggest the environment back then was mostly grassy savanna. However, the way in which those ratios fluctuate suggests riverside forests also cut through this area. Oxygen isotope ratios that are closely linked with climate also suggest the presence of streams, researchers added". In other words much the same environment as is found today through much of the Sahel region of Africa. Grassland with forest along the rivers. Nothing 'beach' about it. "a backflow from Eurasia of, say, 1% (a huge figure for most of Africa)" Well mt-DNA M and several R-derived haplogroups look to be definitely backflows from Eurasia and are more than just trivial components in Northeast Africa. And Y-DNA E could well represent backflow as well. And that haplogroup is very widespread and common through much of Africa.

"It was a provocation, lol". I realised that, but couldn't resist. So well done. However I noticed something interesting in the Spittoon Neanderthal paper: "There are some theories, however, of how Neanderthals contributed to modern humans, including that they gave us some sort of 'hybrid vigor,' according to Peter Parham" So I'm not the only one who believes hybrid vigour has been an important driving force during our development. So far I've not mentioned my idea that hybrid vigour was at least partly responsible for the expansion of the mt-DNA R/Y-DNA MNOPS expansion from SE Asia. In that region we appear to have a mixing of two separate lines: mt-DNA M/Y-DNA F and mt-DNA N/Y-DNA C. Hybrid vigour is unlikely to be the complete story though, as a mixing of two technologies would also aid the subsequent expansion.